Former U.S. Ambassador to Germany, John Kornblum, says he expects "there will be an arrangement" to allow the NSA whistleblower to return to the U.S.

In an exclusive interview with German television, NSA whistleblower Edward Snowden discussed reports of government death threats and dismissed President Obama's calls to return home, saying he would face a "show trial."

Snowden was interviewed by German journalist and documentary filmmaker Hubert Seipel at an undisclosed location in Russia. It aired late Sunday night on Germany's main public broadcaster ARD.

"These people, and they are government officials, have said they would love to put a bullet in my head or poison me when I come out of the supermarket, and then watch as I die in the shower," he said.

Despite these “significant threats,” Snowden said he was "sleeping well" and appeared generally optimistic about his fate, even though he's wanted by U.S. authorities on treason charges for disclosing details of the NSA's vast intelligence gathering operation that monitored millions of phone calls and emails around the world.

"I think it has become increasingly clear that these leaks didn't cause harm, in fact served the public good," Snowden said, arguing the U.S. government will find it "increasingly difficult to maintain sort of an ongoing campaign against someone who the public agrees acted in the public interest."

In an interview on German TV ahead of the Snowden broadcast, former US ambassador to Germany, John Kornblum, said he believed "there will be an arrangement" to allow Snowden to return to the States.

In the wide-ranging, half-hour interview, Snowden did not reveal much that hasn't already come out as a result of his leaks to international newspapers or in previous interviews, including the online Q&A session he held last week on the "Free Snowden" website.

He again ruled out returning to the U.S., saying if he was charged with treason under the espionage act he would have no chance of a fair trail because the act does not allow defendants to testify in front of a jury.

"The espionage act, from 1917, was intended for people who were selling documents to foreign governments or blowing up bridges or sabotaging communications, not for people serving the public good," Snowden said. "I think it's illustrative that the president says someone should face the music when he knows the music is a show trial."

Snowden also reiterated his claims that the government's own reports have shown the NSA programs "have no value, they have never stopped a terrorist attack in the U.S. and they have marginal utility at best for other things...We don't need these powers. They are worthless," he said.